From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail333.us4.mandrillapp.com ([205.201.137.77]:60565 "EHLO mail333.us4.mandrillapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751259AbcCAFi7 (ORCPT ); Tue, 1 Mar 2016 00:38:59 -0500 Received: from pmta03.dal05.mailchimp.com (127.0.0.1) by mail333.us4.mandrillapp.com id hqklf6174noe for ; Tue, 1 Mar 2016 05:38:58 +0000 (envelope-from ) From: Subject: Patch "bcache: Change refill_dirty() to always scan entire disk if necessary" has been added to the 3.14-stable tree To: , , Cc: , Message-Id: <1456810737127236@kroah.com> Date: Tue, 01 Mar 2016 05:38:58 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled bcache: Change refill_dirty() to always scan entire disk if necessary to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bcache-change-refill_dirty-to-always-scan-entire-disk-if-necessary.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 627ccd20b4ad3ba836472468208e2ac4dfadbf03 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Sun, 29 Nov 2015 18:47:01 -0800 Subject: bcache: Change refill_dirty() to always scan entire disk if necessary From: Kent Overstreet commit 627ccd20b4ad3ba836472468208e2ac4dfadbf03 upstream. Previously, it would only scan the entire disk if it was starting from the very start of the disk - i.e. if the previous scan got to the end. This was broken by refill_full_stripes(), which updates last_scanned so that refill_dirty was never triggering the searched_from_start path. But if we change refill_dirty() to always scan the entire disk if necessary, regardless of what last_scanned was, the code gets cleaner and we fix that bug too. Signed-off-by: Kent Overstreet Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/md/bcache/writeback.c | 37 ++++++++++++++++++++++++++++++------- 1 file changed, 30 insertions(+), 7 deletions(-) --- a/drivers/md/bcache/writeback.c +++ b/drivers/md/bcache/writeback.c @@ -323,6 +323,10 @@ void bcache_dev_sectors_dirty_add(struct static bool dirty_pred(struct keybuf *buf, struct bkey *k) { + struct cached_dev *dc = container_of(buf, struct cached_dev, writeback_keys); + + BUG_ON(KEY_INODE(k) != dc->disk.id); + return KEY_DIRTY(k); } @@ -372,11 +376,24 @@ next: } } +/* + * Returns true if we scanned the entire disk + */ static bool refill_dirty(struct cached_dev *dc) { struct keybuf *buf = &dc->writeback_keys; + struct bkey start = KEY(dc->disk.id, 0, 0); struct bkey end = KEY(dc->disk.id, MAX_KEY_OFFSET, 0); - bool searched_from_start = false; + struct bkey start_pos; + + /* + * make sure keybuf pos is inside the range for this disk - at bringup + * we might not be attached yet so this disk's inode nr isn't + * initialized then + */ + if (bkey_cmp(&buf->last_scanned, &start) < 0 || + bkey_cmp(&buf->last_scanned, &end) > 0) + buf->last_scanned = start; if (dc->partial_stripes_expensive) { refill_full_stripes(dc); @@ -384,14 +401,20 @@ static bool refill_dirty(struct cached_d return false; } - if (bkey_cmp(&buf->last_scanned, &end) >= 0) { - buf->last_scanned = KEY(dc->disk.id, 0, 0); - searched_from_start = true; - } - + start_pos = buf->last_scanned; bch_refill_keybuf(dc->disk.c, buf, &end, dirty_pred); - return bkey_cmp(&buf->last_scanned, &end) >= 0 && searched_from_start; + if (bkey_cmp(&buf->last_scanned, &end) < 0) + return false; + + /* + * If we get to the end start scanning again from the beginning, and + * only scan up to where we initially started scanning from: + */ + buf->last_scanned = start; + bch_refill_keybuf(dc->disk.c, buf, &start_pos, dirty_pred); + + return bkey_cmp(&buf->last_scanned, &start_pos) >= 0; } static int bch_writeback_thread(void *arg) Patches currently in stable-queue which might be from kent.overstreet@gmail.com are queue-3.14/bcache-prevent-crash-on-changing-writeback_running.patch queue-3.14/bcache-change-refill_dirty-to-always-scan-entire-disk-if-necessary.patch